1. Technical Field
The present inventive concept relates to a semiconductor device having a power rail.
2. Discussion of the Related Art
A logic cell of a semiconductor device is an integrated structure of a semiconductor circuit for performing a specific function. The logic cell may be pre-designed in various ways as an individual module and optimized to satisfy a plurality of specific constraints. The pre-designed logic cell is called a standard cell. A desired circuit may be designed using various standard cells.
Standard cells are subject to the constraints of design rules for efficient space utilization. As miniaturization and integration processes of semiconductor devices develop, critical dimensions of design rules are gradually being reduced. Accordingly, securing a margin of a ground rule, that is, securing a minimum distance between internal patterns is becoming an important challenge to prevent a short circuit between the patterns. The minimum distance can be secured only when constraints such as dispersion uniformity of critical dimensions and line edge roughness (LER) of patterns are satisfied.